That’s rich. Socialist Zohran Mamdani has declared billionaires shouldn’t exist, but it’s unlikely he’d be the front-runner to become the Big Apple’s next mayor if it wasn’t for one — far-left kingmaker George Soros, financial records reviewed by The Post show. Mamdani recently told NBC News’ “Meet the Press, “I don’t think that we should have billionaires, frankly” while doubling down on his plan to jack up property taxes on “richer and whiter neighborhoods” if elected mayor. But in less than a decade, Soros’ ultra-woke grant-making network Open Society Foundation has indirectly funneled a combined $37 million to the Working...